The present invention is concerned with a retractable guard means which temporarily covers protectively the cutting edge of a projecting movable cutter for severing sections from carton sealing tape fed from tape applying mechanism in a carton sealing machine. The tape applying mechanism and movable tape cutter preferably employed in the present invention are disclosed in detail and their actions described at length in the copending patent application of Warshaw et al. Ser. No. 645,718 filed Dec. 31, 1975, and the disclosure thereof is embodied herein by reference.
The retractable guard means covers the cutting edge of the tape cutter only when the latter is in a projecting position. When a carton advances through the machine for application of lengths or sections of the tape which are to be applied for anchoring and sealing infolded bottom and/or top flaps the cutter is uncovered by its guard means. However, when there are no cartons traveling through the machine, so that a tape wipe-on means which is movably supported by a movable carrier and the cutter extend into such carton-free path, such as by projection from the tape applying mechanism assembly whether the latter is mounted in the machine or during removal thereof as well as after the removal, the cutter guard covers the cutter's tape cutting edge so as to avoid injury therefrom, and this guard is automatically moved to such protective position by such projecting movement of these equipment parts.
It is a general object of the present invention to embody such cutter edge guarding means in the tape applying assembly that is relatively simple in construction and economical to install while being reliable in protective function when most needed.
A more specific object of the invention is to assure automatic guard covering of such cutter edge when an operator need to remove any such tape applying assembly for simple replacement of the exhausted supply roll of adhesive tape, so that an inattentive operator will be protected from possible hand injury.
A further object of the invention is to embody with the movable cutter manipulative mechanism which assures automatic movement of the cutter guard to its protective position by the action of a swinging tape wipe-on means, e.g., a roller.
The mechanism of the tape applying assembly as embodied in a carton sealing machine includes a retractable guard means protectively covering the cutting edge of cut-off means or a cutter when the latter is in a projecting idle position. This assembly includes a movable carrier which supports tape wipe-on means, e.g., a roller, that is located in a path of advance of a carton through the machine when this assembly is mounted in the machine, and it will be retractably moved by such carton advance. It also includes additional shiftable carrier means that supports the cutter for moving thereby its cutting edge across a path of travel of the tape to the advancing carton for severance of the tape as the section of the latter of desired length is applied to the carton. This assembly also includes means to retract the guard means for uncovering the cutter's cutting edge while the carton advances past the tape wipe-on means.
The guard means preferably is carried by swinging arm means pivotally supported on frame structure of the tape applying mechanism assembly, and this swinging arm means is suitably linked to the movable carrier which supports the tape wipe-on means. In a preferred embodiment this swinging arm means is in the form of an elongated lever arm of the third class pivotally mounted to the assembly frame structure at one point and carrying the guard means at another point spaced from the pivot point, with the linking means being pivotally connected to this lever arm between these points. The tape wipe-on carrier means preferably is in the form of a pivoted lever arm carrying this tape wipe-on means at its outer end with this lever arm and the guard carrying arm in this embodiment preferably being connected directly together by the linking means. Preferably this linking means is in the form of a single link pivotally connected at spaced points to the guard carrying arm and to the wipe-on arm, with the latter being a lever arm of the first class having its end opposite that carrying the wipe-on means being linked to the guard carrying arm, and with this wipe-on arm being pivotally mounted to the assembly frame structure at a point intermediate this arm's ends. It is also preferred that the manipulative tape cutter means be in the form of a lever arm which carries the cutting edge at one end and is coaxially pivotally and independently mounted at the pivot point of the wipe-on arm to the frame structure while the other end of this cutter arm is connected to the frame structure by resilient biasing means.